Insecticide resistance and role in malaria transmission of Anopheles funestus populations from Zambia and Zimbabwe
Insecticide resistance and role in malaria transmission of Anopheles funestus populations from Zambia and Zimbabwe
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DOI：
10.1186/s13071-014-0464-z
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发表时间：
2014-10-08
影响因子：
3.2
通讯作者：
Coetzee, Maureen
中科院分区：
文献类型：
--
作者：
Choi, Kwang S.;Christian, Riann;Coetzee, Maureen
背景：在非洲南部的funestus按蚊种群中描述了两个线粒体DNA分支。进化枝I在整个非洲大陆都很常见，而进化枝II只在莫桑比克和马达加斯加发现。这些分支的具体生物学地位目前尚不清楚。我们研究了每个进化支在恶性疟原虫传播中可能发挥的作用以及对杀虫剂的抗性状况。来自津巴布韦和赞比亚的蘑菇。方法：2013年和2014年分别在赞比亚恩切伦格区和津巴布韦宏德谷采集室内蚊虫。对野生雌虫及其子代进行了世卫组织药敏试验、增效试验和抗性强度试验。ELISA法检测恶性疟原虫环孢子子蛋白。用标准分子方法对标本进行了种和mtDNA枝的鉴定。结果：在这两年的收集中，津巴布韦的样本都是进化支I，而赞比亚的种群包括80%的进化支I和20%的进化支II。ELISA检测结果显示，2013年津巴布韦和赞比亚的总感染率分别为2.3%和2.1%，2014年为3.5%和9.2%。在进化枝之间没有观察到显著差异。所有种群对拟除虫菊酯和氨基甲酸酯均有抗性，但对有机氯和有机磷敏感。增效试验表明，拟除虫菊酯抗性是由细胞色素P450单加氧酶介导的。抗性强度试验显示，连续接触拟除虫菊酯8小时后存活率较高，但接触苯虫威的结果与敏感对照相同。结论：首次记录了安。发生在赞比亚的真菌mtDNA进化支II。没有证据表明这些分支是生物学上不同种群的标志。An的能力。长期暴露于拟除虫菊酯类杀虫剂的赤霉病对这些杀虫剂在南部非洲的使用产生了严重影响，无论是通过低剂量杀虫剂还是室内杀虫剂，都应紧急实施耐药性管理战略。
Background: Two mitochondrial DNA clades have been described in Anopheles funestus populations from southern Africa. Clade I is common across the continent while clade II is known only from Mozambique and Madagascar. The specific biological status of these clades is at present unknown. We investigated the possible role that each clade might play in the transmission of Plasmodium falciparum and the insecticide resistance status of An. funestus from Zimbabwe and Zambia.Methods: Mosquitoes were collected inside houses from Nchelenge District, Zambia and Honde Valley, Zimbabwe in 2013 and 2014. WHO susceptibility tests, synergist assays and resistance intensity tests were conducted on wild females and progeny of wild females. ELISA was used to detect Plasmodium falciparum circumsporozoite protein. Specimens were identified to species and mtDNA clades using standard molecular methods.Results: The Zimbabwean samples were all clade I while the Zambian population comprised 80% clade I and 20% clade II in both years of collection. ELISA tests gave an overall infection rate of 2.3% and 2.1% in 2013, and 3.5% and 9.2% in 2014 for Zimbabwe and Zambia respectively. No significant difference was observed between the clades. All populations were resistant to pyrethroids and carbamates but susceptible to organochlorines and organophosphates. Synergist assays indicated that pyrethroid resistance is mediated by cytochrome P450 mono-oxygenases. Resistance intensity tests showed high survival rates after 8-hrs continuous exposure to pyrethroids but exposure to bendiocarb gave the same results as the susceptible control.Conclusions: This is the first record of An. funestus mtDNA clade II occurring in Zambia. No evidence was found to suggest that the clades are markers of biologically separate populations. The ability of An. funestus to withstand prolonged exposure to pyrethroids has serious implications for the use of these insecticides, either through LLINs or IRS, in southern Africa in general and resistance management strategies should be urgently implemented.